1. Technical Field
The present disclosure relates to communication technologies supporting licensed and unlicensed bands, and more particularly, to operation methods of a communication node supporting a licensed assisted access (LAA).
2. Related Art
Various wireless communication technologies are being developed in accordance with advancement of information communication technologies. Wireless communication technologies may be generally classified into technologies using licensed bands and technologies using unlicensed bands (e.g., industrial-scientific-medical (ISM) band) according to bands used by respective technologies. Since a licensed band is exclusively used by a specific operator, the technology using the licensed band may provide better reliability, communication quality, etc. than that using an unlicensed band.
There exists, as a representative cellular communication technology using the licensed band, a Long Term Evolution (LTE) or LTE-Advanced standardized in a 3rd generation partnership project (3GPP). Thus, a base station or a user equipment (UE) supporting LTE or LTE-Advanced may transmit or receive signals through the licensed band. Also, there exists, as a representative wireless communication technology using the unlicensed band, a wireless local area network (WLAN) defined in IEEE 802.11. Thus, an access point or a station supporting the WLAN may transmit or receive signals through the unlicensed band.
Meanwhile, as mobile traffics are increasing explosively, additional licensed bands are required in order to process such the increasing mobile traffics through licensed bands. However, licensed bands are limited resources. Since a licensed band is obtained usually through an auction held among operators, astronomical investment may be demanded for obtaining the additional licensed bands. In order to resolve the above-described problem, a method for providing LTE or LTE-Advanced services through the unlicensed band may be considered.
In the case that LTE or LTE-Advanced services are provided through the unlicensed band, unnecessary information may be transmitted to a communication node which does not configure an unlicensed band cell. Also, due to characteristics of the unlicensed band (e.g., an opportunistic channel access manner, limitation of a maximum transmission duration (or, maximum channel occupancy time), etc.), a subframe structure, a scheduling method, and so on defined for the licensed band may not be used in the unlicensed band.
Meanwhile, this description on the related arts is written for understanding of the background of the present disclosure. Thus, information on other than conventional technologies, which are already known to those skilled in this technology domain to which the technologies of the present disclosure belong, may be included in this description.